108 METHO'DS OF OOMMUNICATIOX FOR FOREST PROTECTION 



it must be carried frequently on pack-horses and saddle-horses and be subjected to 

 rough field usage it is essential that it be self-contained and well protected against 

 external injury. Finally, light weight is important. To meet these requirements it 

 was necessary to design an entirely new -style of portable set. The 1375- A set of the 

 Northern Electric Company was the result, and it has been adopted as standard by 

 the Forestry Branch. No other type of test set may be purchased except with the 

 approval of the district inspector. 



The weight of the 1375-A set, however, was still found to be a handicap to its 

 use -by moving patrol, especially foot patrolmen, and a still lighter instrument was 

 designed. This is the 1004-A set of the Northern Electric 'Company which weighs oTily 

 2* pounds with battery and may be carried in the pocket. It uses the military method 

 of vibratory signals and has been standardized for use by the Forestry Branch. 



Finally, occasions sometimes arise when it becomes desirable to provide more 

 com'plete telephone service at temporary stations than either of the above sets is 

 capable of affording, but where extra light weight is not essential. As a rule this is 

 accomplished by using a wall set, but obviously these are poorly adapted to rough 

 methods of transportation. To meet this requirement a combination of certain 

 standard equipment into a single set known as the Forestry Branch emergency set 

 No. 1-A has been devised. These sets are not .available for purchase but may be 

 assembled locally or secured from the district inspector. 



Section 80 Forestry Branch Portable Telephone 



1 USE IN FOREST PROTECTION 



The special portable telephone (Northern Electric 1376-A, Fig. 6<2) being adapted 

 for use on any line employing code signalling by polarized bells lias a wide application 

 in forest protection wherever its weight of 9 pounds is not a serious bar. It is more 

 widely applicable than the Adams hand set herein described, although considerably 

 more expensive, also. The particular .advantages that this set possesses are as 

 follows : * . 



(1) It is entirely self-contained in a stout leather case and capable of with- 

 standing very rough usage. 



(2) It will call by bell signals any permanent station or any temporary station 

 provided with bells. It will also call any station equipped only with a howler. 



(3) It is provided with a protector and, therefore, may be left connected to the 

 line without fear of injury from lightning. 



(4) It is provided with a buzzer and, therefore within limits, may receive a 

 signal from a distant station. 



(5) Although normally it uses only a small flash-light battery, it may, if desirable, 

 be equipped with ordinary dry cells. 



These advantages are offset only by the weight and cost of the set, and' where 

 the former is not very objectionable the set should be used. 



In general, portable sets are a useful feature of the equipment of rather highly 

 specialized forces only. They presuppose the existence of a fairly well developed 

 system of lines of 'communication and of time standards, which make it imperative 

 that these lines be available for use by the field staff regardless of the location of per- 

 manent stations. No telephone system can be provided' with permanent stations so 

 numerous that considerable time will not be required to reach them from the average 

 point along the line. Both cost and electrical load requirements restrict the number 

 of possible stations very materially. Wherever, therefore, the average time required 

 to reach a permanent station in order to send an emergency message is greater than 

 the protection standards will permit, portable sets must be made a feature of the 

 -equipment. 



